JPH0417600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coupling method for integrating a dome-shaped speaker diaphragm and a voice coil.

[Conventional technology]

Conventionally, methods for coupling a speaker diaphragm and a voice coil wound around the diaphragm are shown in FIGS. 4 to 7.
The one shown in the figure is known. In Figure 4,
Reference numeral 11 is a dome-shaped diaphragm, and the diaphragm is
It is formed from metals such as Al and Ti, ceramics such as B ₄ C and Al ₂ O ₃ , or a mixture thereof. An insulated steel wire is wound around the rising portion of the dome-shaped diaphragm 11 as a voice coil 12 . The diaphragm 11 and the voice coil 12
are bonded to each other by an adhesive 14. The diaphragm 11 and voice coil 1 are integrated through this connection.
The diaphragm unit consisting of 2 (hereinafter referred to as a unit in which a diaphragm and a voice coil are integrated) is a diaphragm unit that is connected between a signal current flowing through the voice coil 12 and a magnet placed close to the voice coil. This action causes piston movement (vibration), which generates sound.

As described above, during actual operation when the diaphragm 11 vibrates, a large current flows through the voice coil 12, so that the temperature of the voice coil and the diaphragm 11 can reach approximately 180°C. In order to withstand this high temperature, heat-resistant polyamide, polyimide, epoxy, or a mixture thereof has been used as the adhesive 14.

Please note that these adhesives require a temperature of approximately 180°C to cure, and after applying the adhesive, a temperature of approximately 180℃ is required.
It was processed in a furnace at 180℃.

In addition, as shown in FIG. 7, a suitable adhesive is installed inside the dome of the diaphragm 11 to prevent deformation or cracking of the diaphragm 11 and the voice coil 12 during winding and curing of the adhesive. Tool 13 was inserted.

[Problem that the invention seeks to solve]

In the conventional method of coupling the speaker diaphragm and voice coil described above, the diaphragm 11 and the voice coil 1
2 and the jig 13 reach a temperature of about 180°C during the curing process of the adhesive 14, so these diaphragms 11,
The voice coil 12 and the jig 13 expand to increase their respective diameters. If the materials constituting the diaphragm 11, the voice coil 12, and the jig 13 have approximately the same thermal expansion, the diaphragm 11 and the voice coil 12 can be connected without any problem. A problem arises if there is a large difference in the thermal expansion of the jig 13.

As an example of the large difference in thermal expansion between the materials constituting the diaphragm 11 and the voice coil 12, the diaphragm 11 is made of ceramic materials such as B ₄ C, Al ₂ O ₃ , etc., and the voice coil 12 is made of copper. This applies to cases where the This B ₄ C, Al ₂ O ₃
A diaphragm 11 made of ceramic materials such as Al, Ti, etc. has recently begun to be used because it enables reproduction up to a high frequency range compared to conventional diaphragms made of Al, Ti, or the like. The coefficient of thermal expansion of this ceramic material is 1/3 to 1/4 smaller than that of copper. A gap is created between the voice coil 12 and the voice coil 12 due to the difference in coefficient of thermal expansion, and the adhesive may flow out or a portion of the adhesive may not be bonded. If the adhesion is incomplete as described above, there is a problem that the voice coil 12 may be disconnected during actual operation.

In addition, in order to reduce the gap between the voice coil 12 and the diaphragm 11, the jig 13 is made of a material with a coefficient of thermal expansion close to that of copper, and the jig is inserted into a dome with a frequency of 11 so that the windings and Usually, the adhesive is hardened, but in this case there is a problem that stress is applied to the diaphragm 11 when the temperature rises, causing the diaphragm 11 to crack.

This invention has been made to solve the above problems, and is a speaker diaphragm and a voice coil that can prevent the diaphragm 11 from cracking and can connect the diaphragm 11 and the voice coil 12 in good condition. The purpose is to obtain a method for combining.

[Means for solving problems]

A method for coupling a speaker diaphragm and a voice coil according to the present invention is to spray a voice coil wrapped around a rising part of a dome-shaped diaphragm using ceramic powder as a thermal spraying powder, so that the ceramic covers the entire surface of the voice coil. A first step of depositing the ceramic so as to cover it, a second step of applying or impregnating an adhesive on the diaphragm and voice coil temporarily bonded in the first step, and applying or impregnating the adhesive. A third step of curing the agent is performed.

[Effect]

In this invention, ceramics are thermally sprayed onto the voice coil, and the ceramics are deposited so that the entire surface of the voice coil is covered with the ceramics, and the diaphragm and the voice coil are temporarily bonded. Since the adhesive applied or impregnated on the diaphragm and voice coil is cured, the diaphragm and voice coil are firmly connected.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1, 2 and 3 relate to one embodiment of the present invention, with FIG. 1 showing a method for forming a temporary bonding layer, and FIG. 2 showing a method for forming a temporary bonding layer, and FIG. FIG. 3 shows the configuration of the combined diaphragm unit and the winding state of the voice coil around the diaphragm.

In FIG. 3, reference numeral 1 is a dome-shaped alumina diaphragm made by a conventionally known thermal spraying method, and there is a dome inside the diaphragm for easy winding of the voice coil 2. A jig 3 made of alumina and having the same quality as the diaphragm 1 is inserted into the diaphragm 1 . In this state, a copper wire covered with a heat-resistant insulation coating, which will become the voice coil 2, is wound around the rising portion of the diaphragm 1. As shown in FIG. 1, alumina powder 5 is thermally sprayed onto the surface of the voice coil 2 using a plasma spraying device 4 to form a temporary bonding layer 6. In FIG. 1, the same reference numerals as in FIG. 3 indicate the same or corresponding parts. Further, the diaphragm 1, voice coil 2, and jig 3 are rotating as shown by arrows in FIG. Reference numeral 8 is a shielding plate;
By providing the shielding plate, the temporary bonding layer 6 is formed only in the necessary portions. Furthermore, during the thermal spraying, in order to suppress the rise in temperature of the diaphragm 1, voice coil 2, and jig 3, they are forcibly cooled by means not shown.

After the temporary bonding layer 6 is formed as described above, a resin adhesive made of a mixture of polyamide and epoxy is applied or impregnated so as to cover the surface of the temporary bonding layer 6, and then placed in a furnace. approx. 180℃
Perform hardening treatment. Through this process, a diaphragm unit in which the diaphragm 1 and the voice coil 2 are firmly connected as shown in FIG. 2 is obtained. In FIG. 2, the same reference numerals as in FIG. 1 or 3 indicate the same or corresponding parts. Further, the reference numeral 7 indicates the adhesive described above.

In this bonding method, the thermally sprayed temporary bonding layer 6 not only brings the diaphragm 1 and the voice coil 2 into close contact, but also serves to restrain the elongation of the voice coil 2 due to thermal expansion that occurs during the curing process of the adhesive 7. Since there is no gap between the plate 1 and the voice coil 2, the adhesive 7 does not leak out.
Therefore, the diaphragm 1 and the voice coil 2 are firmly coupled. Further, since the temporary bonding layer 6 is a film formed by thermal spraying, it contains a large number of pores. In the curing process of the adhesive 7, the adhesive is fixed so as to cover the entire surface of the temporary bonding layer 6 including a large number of pores. The surface of the plate 1 is reached, and the diaphragm 1, voice coil 2, and temporary bonding layer 6 are firmly bonded to each other. By using alumina, which is the same material as the diaphragm 1, for the jig 3, the thermal expansion of the diaphragm 1 and the jig 3 is the same, and cracking of the diaphragm 1 during the curing process of the adhesive 7 is prevented. Does not occur. Further, even during actual operation, the expansion of the voice coil 2 is restrained by the temporary fixing layer 6, so that changes in dimensions are reduced.

In the above embodiment, the diaphragm 1 is made of alumina made by a thermal spraying method, but it can be made of boron carbide or other ceramics, or made of ceramic mixed with metal or polymer. You can expect good results. Furthermore, the method for producing the diaphragm 1 is not limited to the thermal spraying method, but may also be produced by a sheet molding method or a pressing method. Further, although a case has been described in which alumina is used as the temporary bonding layer 6 in the same manner as in the diaphragm 1, the same effect can be obtained by using other ceramics as in the diaphragm. It is desirable that the diaphragm 1 has a small weight, and is preferably made of a material with a low specific gravity, such as boron carbide or alumina.

〔Effect of the invention〕

As explained above, this invention combines a dome-shaped diaphragm made of ceramics, a mixture of ceramics, metals, and/or polymers, and a voice coil wound around the rising part of the diaphragm. In a method for coupling a speaker diaphragm and a voice coil, ceramics is thermally sprayed onto the voice coil as a thermal spraying powder, and the ceramic is deposited so as to cover the entire surface of the voice coil, and the diaphragm and voice coil are bonded together. a first step of temporarily bonding; a second step of applying or impregnating an adhesive such as resin on the diaphragm and voice coil temporarily bonded in the first step;
The third step of curing the applied or impregnated adhesive prevents the diaphragm from cracking and allows the voice coil and diaphragm to be firmly bonded, resulting in a highly reliable diaphragm. There is an effect that can be obtained.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention, with Figure 1 being a configuration diagram showing one state in the joining process, Figure 2 being a partial sectional view of the diaphragm unit, and Figure 3 being a partial cross-sectional view of the diaphragm unit. 4 is a partial sectional view showing one state in the manufacturing process of the diaphragm unit, FIGS. 4 to 6 show a conventional diaphragm unit, FIG. 4 is a partially longitudinal front view, and FIG. FIG. 6 is a plan view, FIG. 6 is a perspective view, and FIG. 7 is a partial sectional view showing one state in the manufacturing process of a conventional diaphragm unit. 1: diaphragm, 2: voice coil, 3: jig,
6: Temporary bonding layer, 7: Adhesive. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A dome-shaped diaphragm made of ceramics, a mixture of ceramics and either metal or polymer, or a mixture of ceramics, metal, and polymer, and a voice coil wound around the rising part of the diaphragm. In a method for coupling a speaker diaphragm and a voice coil, the method includes spraying ceramics as a spray powder onto the voice coil,
a first step of depositing ceramics so that the ceramics cover the entire surface of the voice coil;
a second step of applying or impregnating an adhesive on the diaphragm and voice coil that have been temporarily coupled in the first step;
A method for coupling a speaker diaphragm and a voice coil, comprising performing a third step of curing the applied or impregnated adhesive.